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SEEDS
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Seed Types: Most Fritillaria
have flat deltoid shaped seed with a marginal wing to aid wind
dispersal. This
type of seed is dry at the point of dispersal, tolerant to desiccation
and
associated with open habitats. In the Fritillaria
Japonica Group the seed are ovoid with an elaiosome to encourage
dispersal by
ants, myrmecochory, and are not tolerant to desiccation. Myrmecochory
is found
in several Japanese spring ephemerals and is associated with woodland
habitats.
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| Seedling Recruitment:
Within Fritillaria
the number of ovules per ovary and flowers per plant varies greatly and
consequently the potential seed output ranges from 10-15 seeds in
higher
altitude Japanese woodland species to 1800 seeds in F.
persica.
Actual seedling recruitment has been reported between zero
and five percent in wild populations. A combination of factors limit
seedling recruitment, for example pollination failure, grazing of
flowers, capsules or seed, insect seed
predators, soil pathogens or loss of viability with age as the testa
(seed
coat) is very thin. Competition from other seedlings or surrounding
vegetation
will cause further seedling mortality. |
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Dormancy, Germination &
Seedling Emergence: One common aspect of all Fritillaria seed is their
undeveloped embryo at the time of dispersal so before the seeds can germinate
the embryo has to complete its development. Post-dispersal embryo
development will only start after imbibition and the rate of embryo growth
increases at lower temperatures. The shoot-root axis in Fritillaria is always
with the root aprical meristem at the base of the seed and as the embryo
develops it expands away from the base. Germination is the point at which
the radical emerges and in Japanese woodland species this is timed to
correspond with leaf fall and is synchronized with root growth in adult bulbs.
In most other Fritillaria species radical emergence starts several
months after root growth in adult bulbs. Optimum temperature for post-dispersal
embryo development and germination is thought to be 4-5˚C. Seedling emergence
in all Fritillaria occurs at or just before the emergence of adult bulbs
from February to July depending on species.
Laurence Hill © 2011
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| Download
Fritillaria
Seeds PDF > |
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| FURTHER
READING |
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| Carasso et. al. 2011. Temperature
control of seed germination in Fritillaria
tubiformis subsp. moggridgei
(Liliaceae)
a rare endemic of the South-west Alps. Seed Science Research, 21: 33-38. |
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Zhang.
1983. Vegetation Ecology and
Population Biology of Fritillaria meleagris
L. at the Kungsangen Nature Reserve, Eastern Sweden. Acta
Phytogeographica
Suecica, 73.
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